Disable SDL2_mixer for emscripten builds

Remove SDL2_mixer from emscripten builds to fix compilation failure.
The emscripten-ports/SDL2_mixer repository was archived in Jan 2024
and has unfixable compilation warnings in music_modplug.c. The port
system internally enforces -sSTRICT -Werror which cannot be
overridden by user flags like -sSTRICT=0.

SDL2 (without mixer) still provides graphics support for games like
Doom and Quake. Audio mixing is optional functionality.

Author: jserv

mk/wasm.mk

@@ -18,10 +18,12 @@ CFLAGS += -mtail-call
 
 # Build emscripten-port SDL
 ifeq ($(call has, SDL), 1)
-# Disable STRICT mode to avoid -Werror in SDL2_mixer port compilation.
-# The emscripten-ports/SDL2_mixer was archived in Jan 2024 and has warnings
-# in music_modplug.c that become fatal errors under STRICT mode.
-CFLAGS_emcc += -sSTRICT=0 -sUSE_SDL=2 -sSDL2_MIXER_FORMATS=wav,mid -sUSE_SDL_MIXER=2
+# NOTE: SDL2_mixer is disabled for emscripten builds because:
+# 1. The emscripten-ports/SDL2_mixer repository was archived in Jan 2024
+# 2. It has unfixable compilation warnings in music_modplug.c
+# 3. The port system internally enforces -sSTRICT -Werror which cannot be overridden
+# 4. Games (Doom/Quake) work without audio mixing, SDL2 alone provides graphics
+CFLAGS_emcc += -sUSE_SDL=2
 OBJS_EXT += syscall_sdl.o
 LDFLAGS += -pthread
 endif
@@ -32,7 +34,6 @@ CFLAGS_emcc += -sINITIAL_MEMORY=2GB \
 	       -s"EXPORTED_FUNCTIONS=$(EXPORTED_FUNCS)" \
 	       -sSTACK_SIZE=4MB \
 	       -sPTHREAD_POOL_SIZE=navigator.hardwareConcurrency \
-	       --embed-file build/timidity@/etc/timidity \
 	       -DMEM_SIZE=0x20000000 \
 	       -DCYCLE_PER_STEP=2000000 \
 	       -O3 \
@@ -63,7 +64,8 @@ $(OUT)/elf_list.js: artifact tools/gen-elf-list-js.py
 	$(Q)tools/gen-elf-list-js.py > $@
 
 # used to download all dependencies of elf executable and bundle into single wasm
-deps_emcc += artifact $(OUT)/elf_list.js $(DOOM_DATA) $(QUAKE_DATA) $(TIMIDITY_DATA)
+# NOTE: TIMIDITY_DATA removed because SDL2_mixer is disabled for emscripten
+deps_emcc += artifact $(OUT)/elf_list.js $(DOOM_DATA) $(QUAKE_DATA)
 
 # check browser version if supports TCO
 CHROME_MAJOR :=